Translation of abstract (English)

Plant modeling is an interesting and challenging field in the interdisciplinary scientific researches for integrating the knowledge in mathematics, biology, botany, agriculture and computer science. In this dissertation on modeling, simulation and visualization of plant growth based on Lindenmayer Systems (L-systems) and Particle Transportation Systems (PT-systems), we propose two possibilities for generating plant structures. The first method is using L-systems based on Bracketed, Stochastic and Parametric L-systems. It is suitable for generating a known plant structure, which is easy to model and decomposes the whole plant structure to small simple components such as production rules. In the second method PT-system is used for simulating the rough structure and fast generating of plant structure by giving predefined plant shape or volume of shoot and root domain. Both methods can be used to generate plant shoots, roots, leaf veins and other branching structures as well. The prototypes of these two methods are designed for incorporation of measured qualitative and quantitative data from actual plants such as internode length and diameter, branch length and diameter, leaf width and length, root length and diameter. These quantitative data are approximated by parameter estimation using Levenberg-Marquardt method based on N-pulses sigmoidal function. All fitted parameters can be used in each prototype to simulate plant growth behavior. Both systems are used to create artificial plant models from natural plants by expertise in L-systems. In order to describe plant structure in a systematic way, we also propose the method for transforming acquisition data to artificial branching network, the so-called inverse problem of L-systems". The inverse problem of L-systems provides the way to reconstruct the branching structure from input images or volume data of the complicated network structures. The actual growing root in soil volume can be scanned by Computed Tomography (CT) scanners and the root structure can be segmented from the volume. The final reconstructed structure is represented in L-systems description based on Bracketed and Parametric L-systems for further use. For the development of root systems and the root growth, the environmental factors in soil profile play an important role. The diffusion equation and Richards equation are used to describe nutrient diffusion and water flow in soil volume, respectively. The root system is growing simultaneously during nutrient diffusion and water flow. Nutrient and water uptake are computed at each time step for the next iteration of growth process. Finally, this dissertation promotes new approaches for modeling and simulation of plant growth depending on environmental factors by using the computer simulation tools. The results obtained in this dissertation can be applied in many disciplinary fields; e.g. agriculture, plant modeling, crop management, economy, etc. The simulation and visualization of plant growth based on L-systems, PT-systems, inverse problem, water flow and nutrient diffusion are presented by our self-developed software tool so-called PlantVR (Plant Virtual Reality).